Heater cut-out for electric lamps.



No.v728,647. PATENTED MAY 19, 1903.

A. J. WURTS.- HEATER GUT-OUT FOR ELECTRIC LAMPS.

APPLIOATIONYIILED JULY 7, 1900. 30 MODEL.

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UNITED STATES Patented May 19, 1903.

PATENT OFFICE.

ALEXANDER JAY WUBTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO GEORGEWESTINGHOUSE, OF PlTTSBURG, PENNSYLVANIA.

HEATER CUT-OUT FOR ELECTR!C LAMPS.

SPECIFICATION forming part of Letters Patent N 0. 728,647, dated May 19,1903.

Application filed July 7,1900. Serial No. 22,829. (No model.)

To all whom, it may concern.-

Be it known that LALEXANDER J AY WURTs, a citizen of the UnitedStates,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and use ful Improvement in HeaterOut-Outs for Electric Lamps, of which the following is a specification.

My invention relates to electromagnetic- |o ally-actuated means forbreaking electric circuits, and has particular reference to such devicesas are employed for breaking the heatercircuits of electric lamps, thelight-giving elements of which are conductors only when heated.

One of the objects of my invention is to provide cut-out devices for thehea ers of alternating current lamps of the character above indicatedwhich shall obviate the hu mming sound ordinarily caused by alternatingcurrents.

A further object of my invention is to provide asimple and inexpensiveform of cut-out which shall have a single point of contact, or

a single point for each pole in case the cut-out is of the double-polevariety, and which shall be especially adapted for use in the hightemperatures to which such devices are subjected.

With these ends in View I have devised the means shown in theaccompanying drawings,

in which- Figure 1 is a View, partially in section, partially inelevation, and partially diagrammatic, of a lamp having a single-polecut-out constructed in accordance with my invention. Fig. 2 is aviewsimilar to Fig. 1, but omitting some of the parts and illustrating aslight modification. Figs. 3 and 4: are plan views of certain details ofthe cut-out. device. Fig. 5

is a view similar to Fig. 1, but showing a double-pole cut-out. Fig. 5is a side elevation of some of the parts of a modified form of adouble-pole cut-out. Fig..6is a plan view of some of the parts shown inFig. 5. Fig. 6 is a detail perspective view of one of the parts shown inFig. 5*. Fig. 7 is a sectional View of a solenoid and core provided withan attachment for drawing one end of the core against one side of thesolenoid when the former is elevated. Fig. 8 is a view of certain partsof a cut-out of modified construction,

and Figs. 9 and 10 are plan views of two of the parts shown in Fig. b.

Electric lamps the light-giving elements of which are formed ofmaterials that are condoctors only when heated as heretofore generallyconstructed have embodied electric heaters located in proximity to thelight-giving bodies or glowers and so arranged and connected as to betraversed by current until the glowers became heated to a conductingtemperature. In some cases means have been provided for withdrawing theheater from the immediate vicinity of the glower,with or withoutinterrupting its circuit, as soon as the glower became conductive, andin other cases the heater was immovable; but means were provided forautomatically interrupting its circuit as soon as the glower becameconductive. Various devices have also been proposed 7cv for breaking theheater-circuit and for withdrawing the heater t'rom the vicinity of theglower; but the means most generally employed has been a solenoid actingupon a core, the latter being connected to the movable member of thecut-out or to the heater, according as the heater-circuit wasinterrupted or the heater itself was moved bodily away from the glower.The operation of such devices has been in the main satisfactory, exceptthat dif- 8o ficulty has been experienced on account of the hummingnoise caused by the vibrations of the solenoid-core when acted upon byalternating currents. It has been attempted to obviate this hummingnoise by providing the core of the solenoid with a cushioning-sheath;but even this by itself failed to entirely overcome the difliculty onaccount of the high temperatures to which the devices were subjected. Ithas also been proposed in some cases to employ a spring of some sort foractuating the movable member of the cut-out in the one direction or theother or to make the movable member itself of spring metal; but thispractice has also been found to be 5 unsatisfactory by reason of thehigh temperatures to which these parts are subjected in the lamps inwhich they are employed.

One of the most satisfactory forms of cutout heretofore employed hasembodied carbon contact-pieces; but these were necessarily ofcomparatively large dimensions on account of the relatively poorconductivity of the material and by reason of the liability of the partsto get out of accurate adjustment.

I obviate all of the difficulties above enumerated by the means shown inthe accompanying drawings, to which reference may now be had, attentionbeing first directed particularly to Figs. 1, 2, 3, and 4.: In thesefigures the glower 1 is formed of a material that is a conductor onlywhen heated, the current being supplied thereto-from a suitable source(not shown) through conductors 2 and 3. The heater 4 for the glowermaybe of any desired construction, and it it is also supplied withcurrent for the purpose of raising the temperature of the glower fromconductors 2 and 3 through a branch'conductor 5 and the contact membersof the cut-out 6. The terminal of the glower that isconnected to theconductor 2 has a ballast device 7 and a solenoid 8 included in circuitbetween it and said conductor. The core 9 ofjthe solenoid is preferablyprovided with a cushioningsheath 10, of asbestos, and with anon-magnetic extension 9, that rests upon athin strip or ribbon 11 offlexible but inelastic metal such, for example, as aluminium-when thesolenoid is not energized. The non-magnetic extension is provided inorder that the rattling noise, which might result if the ribbon 11 weredrawn up into engagement with the bottom of the solenoid, may beavoided. One end of this strip or ribbon 11 is preferably considerablythinner than its other portions in order that the upward movement ot'the solenoidcore when the solenoid is energized may serve to bend thestrip only at that end. The said end is fastened to a terminal block 12,mounted upon a supporting-plate 13, of non-conducting material, and itsother end is provided with a contact-piece 14 in the form of a wire,preferably of silver or platinum, this wire being shown as extendingtransversely to the length of the ribbon 11 and having its ends bentaround the edges of the ribbon and against its top, so as to clamp thewire firmly in position. The contact-piece 14: makes contact with a wire15, that extends at right angles with wire 14 and has its ends bent andclamped around the top of a terminal block 16, supported upon the plate13. The core extension 9 is loosely connected to the ribbon 11 by meansof a pin or screw 17, that projects through a relatively large openingin the ribbon and the head of which is at a distance from the end of thecore consideremployed for the same purpose is obviated. In Fig. 2the'several parts are the same as the corresponding parts shown in Fig.1, except that the non-magnetic extension 9 of the solenoid-core isrigidly fastened to the ribbon 11. Inasmuch as the one end of the ribbon11 is immovably attached to the block 12 and the maximum degree offlexibility is adjacent to said block, the upward movement of the corewhen the solenoid is energized will draw its upper end into engagementwith the solenoid, as indicated in the drawings. In the constructionshown in these figures the ribbon 11 is extremely flexible adjacent tothe block 12, as above: stated, but has no spring action, the weightofthe solenoid-core being sufficient to depress the ribbon and effect theclosing of the circuit when the solenoid is deenergized and to maintainthe circuit closed until the core is again raised by the action of thecoil.

Referring now to Figsr5 and 6, the glower l, the heater 4, and their:circuits are or may be the same asthose shown in the figures alreadydescribed, except in so far as modifications are made to adapt theapparatus to a double-pole cut-out, and hence the description alreadygiven may be read in conection with these figures so far as the same maybe applicable. In these figures the non-conducting plate 13 supports twoterminal blocks 12 and 12, that respectively have fastened to themstrips or ribbons 11 and 11 these strips being respectively providedwith contact-terminals 14 and 14:, which respectively engage with thecontact-terminals15 and 15", respectively mounted on blocks 16 and 16the construction and operation of these parts being substantially thesame as the corresponding parts already described. The connectionbetween the solenoid-core 9 and the ribbons 11 and 11 is made by meansofa non-magnetic extension 9", a block or plate 18 of non-conductingmaterial, to which the extension 9 may be and preferablyis rigidlyattached, and wires 19 and 19, mounted in said block or plate andrespectively bent to form loops through which the ribbons 11 and 11project. This arrangement affords a loose connection between thesolenoid-core and the ribbons, so that when the former is drawn upwardby magnetic action the ribbons will serve to hold it in contact with oneside of the solenoid, and thus prevent vibration.

In Figs. 5 and 6 the parts differ from What is shown in Figs. 5 and inthat a small silver or platinum block or plate 20 is set into each ofthe terminal blocks 16 and 16 in lieu of clamping wires to the tops ofsaid posts. In the construction shown in these figures the wires 19 and19 for making connection between the ribbons and the extension 9 of thesolenoid-core 9 are also dispensed with, the block 18 being providedwith lugs 21 and 21 on its lower side, respectively adjacent to itslateral edges, these lugs being provided with openings 22 and 22,through which the ribbonslland ll respectivelyproject. This block 18 maybe formed of porcelain or other suitable non-conducting material, andits construction is such that when the core is drawn upward the ribbonswill rest against its lower side substantially throughout its Width,they being thus securely held against vibration, and all noise incidentto such vibration being thus avoided.

In each of the modifications above described the solenoid-core issupported in unstable equilibrium, and hence when raised by the solenoidit will tend to incline to one side, so as to rest against the innerwall of the solenoid. When in this position,the devices. shown in Figs.5, 5 and 6 as embracing the strips 11 and 11 will obviously grip thesaid strips closely, and consequently there will be little, if any,tendency for the parts to vibrate.

In case any special means other than that already described is desiredor needed for drawing the solenoid-core into engagement with thesolenoid and holding it in such position against vibration any one of aconsiderable variety of devices may be utilized. One form of such deviceI have shown in Fig. 7, this being a strip of metal 23, fastened to thetopof the solenoid at one end and having its other endprojecting'downward at an angle to the axis of the solenoid, so that apin 24:, projecting upward from the top of the solenoid-core, will beguided in such manner as to deflect the upper end of the core and forceit into engagement with one side of the solenoid. As I have alreadyindicated, it is obvious that any one of a considerable variety ofdevices may be employed to effect the desired result.

Referring now to Figs. 8, 9, and 10, which show a single-pole cut-outdevice, the terminal block 16 is shown as provided with a contact piece20, set into a socket which may be a saw-cut of such width as to firmlyhold the contact-piece therein, this construction being the same as thatillustrated in Fig. 5. The movable member of the cut-out in this formofthe device comprises a thin flexible ribbon similar to that of thepreceding figures; but in this case this ribbon 11 is reinforced for thegreater portion of its length on both sides by means of strips 25 ofrelatively inflexible materialsuch, for example, as phosphor-bronze-theribbon being preferably clamped between said strips by means of one ormore rivets. The portion of the ribbon l1 that projects beyond the endsof the stiffening-strips constitutes a flexible inelastic hinge, andtherefore serves the same function in that respect as the ribbonsheretofore described. The ribbon in this instance is fastened to theterminal block 12 by forcing its free end into a recess 26, cut in theouter face of the block, this being a secure and at the same timeinexpensive and ready means for attaching the ribbon to the block.

I have also shown another and very simple means for attaching thenon-magnetic core extension 9 to the ribbon 11 and thereinforcing-plates25. This comprises a slot 27 cut in one edge of theribbon and the reinforcingplates, into which a reduced portion of theextension 9 is inserted and in which said portion fits closely, so as tomake a rigid connection. This aifords a secure means of attachment andalso one whichpermits of ready assembling and detaching of the partswhen desired.

Other modifications may of course be made Without departing from thespirit and scope of my invention, and I therefore desire it to beunderstood that the invention is not limited to the specific details setforth.

I claim as my inventiont 1. In aheater cut-out for electric lamps, thecombination with a solenoid and its core, of stationary terminals and aflexible and substantiallynon-resilient metal ribbon attached,

at different points to the solenoid-core and to one terminal and havinga contact-piece which is held in engagement with the other stationaryterminal by gravity when the solenoid is denergized.

2. A heater cut-out for electric lamps, comprising a solenoid, a coretherefor, two stationary terminals, a flexible and substantiallynon-resilient metal ribbon rigidly attached at one end to one stationaryterminal, and to the solenoid-core at a point between its ends, andhaving a contact-piece that is held in engagement with the other contactterminal by gravity when the solenoid is denergized.

8. A heater cut-out for electric lamps, comprising two stationaryterminals, a flexible and substantially non-resilient movable memberrigidly fastened to one of said terminals, a solenoid, and a coreprovided with a cushioning-sheath and attached to said movable member insuch position as to hold it in engagement with the other terminal whenthe solenoid is deenergized.

4. In a heater cut-out for electric lamps, a movable member comprising aflexible and substantially non-resilient metal ribbon having acontact-wire clamped to one end thereof and stationary contact-terminalsto one of which said ribbon is attached and with the other of which thecontact-wire is held in engagement by gravity.

5. A heater cut-out for electric lamps having two terminal blocks,.asolenoid and a solenoid-core, a flexible and substantially nonresilientmetal strip having one end rigidly fastened to one of the terminalblocks, and provided with reinforcing-strips and with a contact-piece'atits free end, the other terminal block having a contact-piece seatedtherein with which the contact-piece on the reinforced strip is held inengagement by gravity when the solenoid is deenergized.

6. In a heater cut-out for electric lamps, a movable member comprising aflexible and substantially non-resilient metal ribbon reinforced for aportion of its length by comparatively inflexible strips, stationarycontact-terminals to one of which said ribbon is attached and with theother of which said ribbon is normally held in engagement by gravity.

7. In a heater cut-out for electric lamps, a movable member comprising 4a reinforced, metal strip or ribbon having a slot in one side or edge,in combination with a solenoid and core, said core having an extensionremovably seated in said slot.

8. In a heater cut-out for electric lamps, the combination with twostationary terminals,each of which has a slot or groove therein, of amovable member comprising a flexible, metal strip reinforced by one ormore comparatively inflexible strips for a portion of its length andprovided at one end with a contact-wire clamped thereon and having itsother end bent and seated in the slot or groove in the correspondingterminal.

9. An electric cut-out comprising a flexible and substantiallynon-resilient member movable to and normally held in circuit-closingposition by gravity and electromagnetic means serving, when energized,to lift said member and hold it in open-circuit position.

10. In an electric cut-out, the combination with a solenoid, of a coretherefor having a non-magnetic extension, a flexible and substantiallynon-resilient ribbon to which said extension is attached and stationaryterminals to one of which said ribbon is attached and upon the other ofwhich it rests under the action of gravity when the solenoid is de=energized.

11. In a heater cut-out for electric lamps, the combination with twostationary terminal blocks one of which has a contact-piece, of aflexible and substantially non-resilient metal ribbon having acontact-piece at one end to engage said terminal-block contactpiece andhaving its other end fastened to the other terminal block, a solenoidand a core therefor having a non-magnetic extension to which the ribbonis attached at a point between its ends.

12. In a cut-out, a solenoid and its core and means for holding the corein a non-vibratory position when the solenoid is energized.

13. In a cut-out for alternating-current circuits, the combination witha solenoid and a cushioned core therefor, of means for mechanicallyholding the core against the inner wall of the solenoid when thesolenoid is energized.

14. A heater cut-out for'electric lamps of the type described comprisinga flexible and substantially non-resilient contact-supporting ribbonmovable to and held in contactclosing position by gravity andelectromagnetic means for deflecting said ribbon to break the circuit.

In testimony whereof I have hereunto subscribed my name this 29th day ofJune, 1900.

ALEXANDER JAY WURTS. Witnesses:

WESLEY G. CARR, BIRNEY HINES.

